2021 Volume 70 Issue 3 Pages 504-510
The Cancer Antigen 72-4 (CA72-4) assay by electrochemiluminescence immunoassay (ECLIA) is a one-step method with only one bound/free separation. However, the method is susceptible to the prozone effect and biotin interference during the immunochemical reaction. Recently, the ARCHITECT CA72-4 reagent, which is based on the chemiluminescence immunoassay (CLIA), has been developed. In this study, we carried out a basic performance evaluation of the CA72-4 reagent by the CLIA method. We used the same residual serum after routine testing by the CA72-4 ECLIA assay has been performed. The CA72-4 value obtained using the ARCHITECT CA72-4 reagent showed linearity up to 300 U/mL. The within-run precision of the CLIA method was excellent for both control samples and pooled sera with a coefficient of variation of less than 5%. The correlation between the ECLIA and CLIA methods was good (regression equation: y = 1.08x − 1.65; correlation coefficient (r): 0.974). Sequential data for CA72-4 showed stability under any storage conditions, including seven days of refrigeration, 24 hours at room temperature, and freezing and thawing. With the CLIA method, biotin did not interfere with the CA72-4 measurements, whereas the ECLIA method decreased the CA72-4 value in a biotin-concentration-dependent manner. Our results indicated that the performance of the CLIA method for the CA72-4 assay was sufficient.
